Abstract

PURPOSE: To identify the role of shock wave lithotripsy (SWL) and flexible ureterorenoscopy (f-URS) on the stone recurrence, in the management of 10-20 millimeter lower pole stone (LPS) with medium follow-up outcomes. MATERIALS AND METHODS: The patients' charts which were treated with SWL or f-URS for LPS between January 2011 and September 2013 were analyzed, retrospectively. Patients who had a solitary 10-20mm LPS were enrolled into the study. In both procedures, patient was accepted as stone free, if complete stone clearance was achieved in the 3rd month abdominal computed tomography. Only patients with a stone free status were evaluated in follow-ups. RESULTS: The stone-free rate was 77.9% (88/113 patients) for the SWL group and 89% (114/128 patients) for the f-URS group (p=0.029). Stone recurrence was detected in 28 (35.4%) patients in SWL group and in 17 (17.2%) patients in f-URS group (p=0.009). Stone types and 24 hour urine sample results were similar between groups (p=0.123 vs p=0.197, respectively). Multivariate regression analysis revealed that f-URS procedure and absence of abnormality in 24 hour urine analysis significantly decreased stone recurrence in medium term follow-up (p=0.001 and p<0.001, respectively). CONCLUSIONS: Our study showed for the first time, that patients which underwent f-URS for LPS, faced less stone recurrence, independent from diet regimen and metabolic evaluation in medium term follow-up. Additionally, presence of abnormality in 24 hour urine analysis increase the stone recurrence risk in follow-ups.

Kommentare
1

The optimal treatment of stones in the lower calices has remained a matter of debate over time. Not unexpectedly the authors of this study presented evidence for a higher stone-free rate (SFR) following fURS (89%) than following SWL (78%) of 10-20 mm large stones in the lower calyx. Moreover, it was shown that this difference also was associated with a significantly higher recurrence risk after SWL than after fURS.

This Table summarizes the most important recordings:
It is not surprising that recurrent stone formation was most common in patients with the lowest SFR and it had indeed been of interest to learn about the risk of recurrent stone formation in those patients from the two groups that were rendered completely stone-free.

Another factor that was considered important was the presence of metabolic abnormalities; 20% in non-recurrent patients compared with 82% (!!) in those with recurrent stones. Obviously an abnormal urine composition was by far the most important risk factor for recurrent stone formation; increasing the risk by a factor of 30!!

Although it is stated that there was a good compliance to recommended diet and medical treatment, the effect of such measures on stone recurrence was obviously low.
But to trust the information given directly by the patients in this regard is risky and there were no data reported to which extent the medical/dietary regimens had affected urine composition.

The authors claim that the anatomy/geometry of the lower calyces was measured but no data are included.

The optimal treatment of stones in the lower calices has remained a matter of debate over time. Not unexpectedly the authors of this study presented evidence for a higher stone-free rate (SFR) following fURS (89%) than following SWL (78%) of 10-20 mm large stones in the lower calyx. Moreover, it was shown that this difference also was associated with a significantly higher recurrence risk after SWL than after fURS.
This Table summarizes the most important recordings:
[img]http://storzmedical.com/images/blog/Ozgor_F.JPG[/img]
It is not surprising that recurrent stone formation was most common in patients with the lowest SFR and it had indeed been of interest to learn about the risk of recurrent stone formation in those patients from the two groups that were rendered completely stone-free.
Another factor that was considered important was the presence of metabolic abnormalities; 20% in non-recurrent patients compared with 82% (!!) in those with recurrent stones. Obviously an abnormal urine composition was by far the most important risk factor for recurrent stone formation; increasing the risk by a factor of 30!!
Although it is stated that there was a good compliance to recommended diet and medical treatment, the effect of such measures on stone recurrence was obviously low.
[img]http://storzmedical.com/images/blog/Ozgor_F1.JPG[/img]
But to trust the information given directly by the patients in this regard is risky and there were no data reported to which extent the medical/dietary regimens had affected urine composition.
The authors claim that the anatomy/geometry of the lower calyces was measured but no data are included.